Is it permissible for the official in charge of a charity to use one of its unused assets or take a portion of its money, with the commitment to return it or the money when needed?

It is not permissible for the acting director of the association to use its resources and tools for personal tasks, even if he intends to return them, because that constitutes a betrayal of trust and an encroachment on the property of others. The donor only gave his money for the charitable institution to dispose of it as it sees fit, so it is not permissible to dispose of it in ways other than what the donors specified or what aligns with their intentions.